The Holstein (may also be known as Holstein-Friesian or Friesian) is a breed of cow known today as the world's highest production dairy animal in Australia. Holstein have very distinctive markings and outstanding milk production. They are large, black and white marked animals that can be anywhere from mostly black to mostly white, or half and half. Size: A healthy calf weighs 30 to 35 kg (about 65-80 lbs.) or more at birth. A mature Holstein cow typically weighs 680 kg (1,500 lbs), and stands 147 cm (58 inches) tall at the shoulder. Holstein heifers should be bred by 15 months of age, when they weigh over 360 kg (792 lbs.) Generally, breeders aim for Holstein heifers to calve for the first time between 23 and 26 months of age. Gestation period is about nine months.